package k2;

public class Stack {
	/**
	 * Node object to store values
	 */
	private Node header;
	public void create(){
		header = null;
	}
	public void push(int x){
		header = new Node(x, header);
	}
	public int pop(){
		int value = header.value;
		header = header.previous;
		return value;
	}
	public boolean isEmpty(){
		if(header != null) return false;
		return true;
	}
}